Snap switches



2 Sheets-Sheet 1 C. W. JOHNSON March 13, 1956 Filed Oct. 21, 1952 'kaflfir I Jamal:

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March 13, 1956 c. w. JOHNSON SNAP SWITCHES Filed Oct. 21, 1952 2 Sheets-Sheet 2 2,738,389 -"SNAP "SWITCHES IIZhEtBfWsJohnson,Bridgewaterg Mnss. .JApplication October 21,..19's2,.senn Nona 5,929

. *4 Claims. (Cl. 2 67) 3 This invention relates to switches "for controlling telec- .rtrietfcircuits, land particularly .to wall SWitChCSk-Dfi the-socalled toggle type usedin homes andoflicesfioncontrolling .t. lig l 1ting-.-circuits.

.. .'1Ehe main-object of the present invention-is to, provide a switch of this type which will be practically noiselessein opaeration, .whilemetaining the essential .featuresi-cf quick .makeand break of the circuit, of avoiding thestopping. of .1. thegparts in intermediate position betweenathe toihand on 1. extremes .of .their movement, of intermittentz ontrembling tcqntactlin .the onposition with-resultant arcing-constituting a fire hazard, and ofreverse creep :of .thelpartsrnutlof .ntheir intended on or off position. Otherobjects of the ...inve ntion include the-provisionof a simple structure -.w.hit :h can be easily. and rapidlyassembl'ed -out.-o f-.inexipensive.components ofwide availabilitytomaike a switch shaping longllifeandtreedom :from -failure-.in..action.

The basic principle employed .in the-novl isnap-switch .to. .attain. noiseless actionis the checking ofstheamoving partstand. ending their travel 'not bystrikingagainststops, butbythewedging on jammingactionand resultantjric- ..ti on.of surfaces travelling with the .movingsparts against other .stationary parts, -herein' by the.-.bindingwaction of .shoes, pivotally attached respectively-to the ..-thumb:,piece tolhespringcarrier andsliding along...-gui 'les. .The

divergent course of each pivot with respect to..-its..associs..ated.guide orother interfering surface, zdisposediin'snom nparallehrelation to the path of travel .of .the -movingsp rt .ancLthe .pivot, causes the --shoe to. bind qont-therguide .and .arre'st .lthe; .motion of the I pivot and thus of...the. thumb ."piecetor spring carrierwithout ..anyapositivetstop,...and ..lherice..sonndlessly. p

Other objects of. the invention, .andfthe manner-Wot attainment of these aims and those already indicated, are as 86bfOl'th-ihlfliflfilftl.

An illustrativeembodimentof theinvention is shown in 50 the accompanying drawings, 'inwhich 5 .Fig. l-is a sideelevation ofthe improved switclifl liig. 2 lplan view thereof andFig. -3- a-z" sideelevationifrom the i oppo'site' side -from Fig. 1, with the-easing orithel mount- 'ng plate' partly broken away.

Fig. 4 -is 'anendelevation ofthe same, with 'the -"ca'sing spams; broken-away.

'rI Figi ibis anendelevation showing onefiend 'tifi ithe switch, and Figs-6; amend elevation-ref the other end.

A Fig. 7 is a side elevation of the thumb piece and single polecbntat maker carriedth'ereby.

Fig. 8 is a similar view of a thumb piece and double pole contact maker.

Fig. 9 is an end elevation of the part shown in Fig. 7. Fig. 10 is a detail showing the bearing for the thumb piece formed in the switch case.

Fig. 11 is a side elevation, Fig. 12 a plan view, and Fig. 13 an end elevation, of the mounting which supports the moving parts, with certain of the latter omitted. egEig. 14 is a plan view of the switch case, showing the stationary contacts and the bulb illuminating the switch. Referring to the drawings, the thumb lever comprises .2 Wa thuinbpieee 1, .oLLucite-nnother translucent plastic, a pivot. rreceived. innno'tehes. S tz'ingthe. switch..case l, .of .i;molded.,.plast ic..or other..,dielect-r ic materiaL- and .anuex- ..;.tension part= 9,=pre'feiab ly metallic, connected by alpivot 5 ,pin .11 .fiited. therein :tor atshoe .13:.slidahly..mounted Won. a guide rod 15 extending parallel stoihe plane of .swing==.of ...the extension 9.

Hole. v17 .imshoe..13...is...slightly.1arge11 l than pivot 11 .to permit the swingof the'.thurnb.,.piece1..needed,to work the switchjbutlbefore.shoe 13 .reachesIthe .bends'in .gu'ide .15 the pa-th..ofi travel .Idf,,pivotl1 'awayfioniithe guide irod .-..l5..;in.ran. u pward arcncentering on ,p'ivot 3. .takes..up...the v.tslaclc. provided in. hole "17. audio ihepassage occupied by guide 15 andflbrings. both;.t'he.;shoe.l3 andlihej'. thumb -,piece ..1 to rest withoutfishocle omsonnd. .The .shoe 'is .p referably...made.;o. .pla'stic...o'f :slig'htly yildable nature. The usual. actuating pull spring19, 'Figs.l.2..and- 4,;is ,J pEOVidEZd'. to accelerate;.t'he;.thurnh ipiecetand carry it and ....e'xtension 9..throngh thirefiilhstndlce'initiated by the users .ltfingersztandtto holdrthegparts securely in either :the onor wolf, position. ..IIhis. spring is .aattahedat .one,en'd. to astud ..,--21t. at.-.th:\bOItOmIdf. extension" 9..ofgthe' 'thumb. lever and ...at. the other: end. .tola,ipin 23.,on a..straight,.spring .carrier nor .tqg'gle lever 25, .pivote'd eat .27 ;to. .a lback .Iplate 29 :in -.-which .the legs. 31 .of .g'ui'r'le. 1'5..are '.fixed .aslbylrivetingor welding. "Thislback, platenis.'mountedfin ilieswitch .case .-7. by sliding..'its.. langes:fildowninto...L}sl;taped..slots '35, Fig d'4',.-.in .one side.-.wall..iofi..theswitch .case 7. TSpring ....earr ier.2'5tis pivotallyratthedratELto. another shoe 39 Q.-.having.af.hole- WherehyJtLisllidihlymounted.on asecond z.,,.-'guide .rod..41 wel'dedstdtbaclg 'platef.f29:.and extending ...across the openi ng therein. "lost motionperrnitting the needed swing bf spring carrier IStis roviHeH -lJymaK- l..ing..this..hole,.or..the, holeain .the ;shoelfor.,piv.ot. 37, or ;...bothpslightly. oversized,..a learanceof LODS lbeing adetquate and.insufiicient. to...allow;ihe.,parts. to, slap .audibly. tnsinceapin 37 through tshoe t'39... travels ..in an. arciabout pivot 27.;.of,.the,.sspring carrier, andrgfiide rodjT lLexten'ds .isin azstraight-tline, the..sam jamming action .occurs with shoe:.39.:as. with .;shoe..13..;to,obring..the =spring carrier -.to .resnaftemhe.desiredamount ohangulanmovementofithe spring ,carr'ienat..eachzsideaof...the zve'rti'cal', ',by .reason vof sthevtlivergent. paIhsNdefinedF-by. pivot 37 .and .rod i41-.as .spring carrier Z'Ssmoves .back-:andlorth. 45 .flrlmnse, manual-.movementmf .the.:thumb.lever...1.tothe .t-s-le'ft int-Big. lzstretches the wl'gg1e;,spripg.;19 :and carries =;.-the-.bottom .end-ahereotrpast. .the linen'oining centers. 23 and 27 as the springrcarr-ier..standstin inclined position .raat uone-rend .torlet-heeother of. its swing. ..Then.tthe spring .tcarrierssnapssoventimthe direotionpttravel -.of..the.bottom wentl of extension9aof thesthumbi leven, pulling the extensnsion :a'longrwithdt -:to.-:completes'the:stroke ofwthedhumb ever: to 1 close .theanircuit. isldentical thut qpposite L movei.z.=menta;-ofsthe partsnoccurs whemithumb zlever 1. is: moved min thetppposite direction. to ,open -::the circuit.

Qlosingsohthe \eireuihiss-eflectedsbwthe entry-.of a ':-.contact.-imakep*z43 itcomprisingavsection ofnsilver tubing tsfixedwonr the-tend 20f." one. of the. larms 45 to-.extension- 9, min .sbflliWfiIfpIWO. .arcuate. silver .,plated metallic. i contact ismembersi47:fixedonmectangularmetal plates 49 equipped with binding screws 50, and slipped into 'slots 51 formed in one end wall of switch case 7. The taper of the opposing faces of contacts 47 toward each other in the upward direction is so slight that contact 43 enters between them soundlessly. The checking of the moving parts is not caused by the entry of contact 43 thus, but as already explained is efiected by the combined binding action of shoes 13 and 39 on their respective guides 15, 41.

. Because spring carrier 25 moves very rapidly under the impulse of its spring 19 when it snaps over, spring in a wall and covered by the usual wall plate.

buffers 52 are mounted on guide rod 41 to act as shock absorbers to help stop the fast traveling shoe 39. These springs are long enough to engage the shoe just before the latter reaches its binding point on guide 41, so as to slow it down. The binding action of the shoe on rod 41 prevents material recoil of the shoe on encountering either spring 52. These springs help prevent reverse creep of extension 9 and its contact 43, by tending to erect spring carrier and hence further stressing spring 19, thus holding extension 9 in place.

Guide rod 15 for thumb lever shoe 13 is bent into U-shape in plan (Fig. 12) so as to provide a slight and resilient endwise movement of the guide. Thus the stresses transmitted to the guide rod by the binding action of shoe 13 in arresting the movement of the thumb lever are cushioned and not transmitted to the back plate and switch case to cause noise; i. e., the shock is transverse to the legs 31 instead of lengthwise thereof.

For easy conversion to a three-way switch, so-called, the other arm of thumb piece extension 9 is also equipped with a contact 44, Fig. 8, and slots 55, Fig. 14, are formed in one end of the switch case 7, into which may he slipped the base portions of a pair of contacts 59, similar to 47. Only one of these slots extends clear through the wall of the case, to permit attachment of a wire to the binding screw 61 of one of the contacts 59, the other of such contacts lacking a binding screw and being connected at 63 to one of the contacts 47. When a three-way hook-up is not Wanted, a plastic filler piece 57, Fig. 5, is inserted to close opening 55.

Continuous illumination of the switch to help locate it in the dark is provided by a neon tube 65, Fig. 14, either loose or if preferred fixed by clip 67 in the bottom of the switch case 7, and permanently connected by leads 69 in the circuit passing through contacts 47 and 59. Translucent thumb piece 1 thus glows with constant light from tube 65.

From the foregoing it will be plain that the arrest of the motion of the parts is caused by the mechanical opposition to further travel of the shoes caused by one surface guiding each of them in a straight path while another surface seeks to compel it to travel in a diverging arcuate path, this action being combined with the friction of each shoe against its guide rod incident to these conflicting motions. Obviously, the guide rods or other interfering or diverting surface need not be straight. The parts are brought to rest so nearly soundlessly that the operation of the switch is inaudible from a distance of approximately four feet when the switch is in place Wear makes no significant change in the action or quietness, because of the steep slope of the arcs.

It is to be noted that the construction provides for the complete assembly of all working parts outside of and before mounting in the switch case 7, save the lamp 65 and the contacts 47, 59. Thus the mounting of all but these latter parts on back plate 29 is the key to high speed economical quantity production, because these parts can be assembled outside the switch case with complete accessibility and accuracy employing jigs and spot welding. Mounting of the back plate with the parts carried thereby as a unit is eifected after assembly by merely sliding the flanges 33 of the back plate down into slots 35. The wiring of the contacts 47, 59, to each other and to lamp is likewise effected outside the case, the contacts being thereafter slipped into their proper slots and the lamp being positioned in the bottom of the case by the leads 69 attached to the contacts 47. Mounting plate or cover 71 is thereafter applied and fixed in position by screws 73 put into lugs 75 formed on the ends of the case.

In the event that any of the moving parts of the switch become disabled or inoperative in use, replacement of the back plate and the parts carried thereby as a unit is easily effected upon merely taking off the mounting plate 71. Thus the improved switch can easily and cheaply be restored to operative condition, instead of having to be discarded and entirely replaced with the attendant trouble of shutting off the current to the switch and disconnecting and then reconnecting the wires thereto.

While I have illustrated and described a certain form in which the invention may be embodied, I am aware that many modifications may be made therein by any person skilled in the art, without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the particular form shown, or to the details of construction thereof, but

What I do claim is:

1. An electric switch having in combination a thumb lever, a spring carrier moving in an are, a spring connecting these parts, shoes pivotally connected respectively to the thumb lever and the spring carrier, and guides for each shoe divergently disposed to the arc of travel of the pivot of such shoe.

2. An electric switch having in combination a thumb lever, a spring carrier moving in an arc, a spring connecting the thumb lever and the spring carrier, a shoe pivotally connected to the latter, and a guide for the shoe divergently disposed with respect to the path of swing of the pivot of the shoe.

3. An electric switch having in combination a thumb lever, a spring carrier moving in an are, a spring connecting the thumb lever and the spring carrier, a shoe pivotally connected to the latter, a guide for the shoe divergently disposed with respect to the path of swing of the pivot of the shoe, and springs alternately engaged by the shoe in its travel in alternate directions along the guide.

4. An electric switch having in combination a mounting plate, an assembly of parts mounted thereon including a thumb lever, a spring carrier, a spring, guides, and shoes pivotally connected to the thumb lever and the spring carrier and traveling along such guides, and a case having slots in its walls receiving the mounting plate and the parts carried thereby as a unit.

References Cited in the file of this patent UNITED STATES PATENTS 1,560,602 Nelson Nov. 10, 1925 1,645,387 Kinney Oct. 11, 1927 1,646,440 Ashford Oct. 25, 1927 1,896,904 Laven Feb. 7, 1933 1,949,694 Poli Mar. 6, 1934 1,969,263 Gaynor Aug. 7, 1934 2,562,420 Furnas July 31, 1951 FOREIGN PATENTS 378,567 Great Britain Aug. 18, 1932 

